I'm trying to fix an older, messy Windows XP installation. There were about 3 security suites installed (Symantec, AntiVir, and 3rd one) and OS updates were completely out of date.

So I began running Windows updates, the last one was SP3 and uninstalled all the security suites (the goal would be to install the free AntiVir Version after all other suites are completely removed). The host was always in a local network behind a firewall during this procedure.

Now, since the last reboot, I can't connect to the Internet anymore. All IP settings are ok, I can even ping google.com (so name resolution and networking must be ok). Any program the tries to connect to the Internet says it can't connect (IE for example). A telnet connection to google.com on port 80 also fails.

Does anyone have some ideas what I could do to make the network work again? Any hints what the problem could be?

8 Answers
8

Make sure Symantec was completely removed (there's a special uninstaller for it on their website) because it has tentacles that like to get stuck into everything and anything that it can and won't always uninstall properly with the standard uninstaller.

That was exactly the problem, I uninstalled Symantec using the Windows uninstaller in the first place. Now after running their special uninstaller, the network connections work again. Thanks!
–
HaesAug 13 '09 at 16:15

Not an direct answer, but I think you will loose less time if you do a full format and reinstall of the OS. From your description, even if you are able to solve the problems, you will still have a truly messy OS at hands.

Restore the system to before the latest updates are done, do a winsock reset. Remove all the AV software. Turn on just the windows firewall for now. Complete all the updates, then install the latest version of your preferred AV.

Check the XP firewall configuration: applications, exception, etc.
You can try to disable the firewall.
Then check among the services if there is some "strange" service related to old antivirus software (some uninstall programs don't work well).

Most probably one of the security suites had a firewall component which wasn't completely uninstalled (removing these can be a pain in the rear). First look in add-remove programs and see if there still are components of the security suites (sometimes they add more than one entry).

If you can't find anything there, try this:

Control Panel -> Network Connections -> (you connection)

Right click on it and select properties

Uncheck anything other than "Internet protocol (TCP/IP)".

Disable and re-enable the interface

If this doesn't work, I agree with Runner: you should look at reinstalling the OS. It probably takes less time and would result in a more stable system.

If at all possible I would be more inclined to do a fresh OS installation. Yes, it's more work, but the end result will be a clean baseline in a known state. Otherwise you run the risk that it'll never be quite right, and the problem may even be made worse by trying to fix it.

The TCP/IP stack can become corrupt in XP. Previous versions of Windows allowed you to uninstall and reinstall TCP/IP which would correct various TCP/Ip related issues. XP however does not allow that. Early versions of XP needed a registry dive to rip out TCP/IP allowing a reinstall (or run a utility called winsockxpfix), but service pack 2 addressed this issue. They added functionality to netsh to wipe and reload tcp/ip.

Run the following command from a command prompt:

netsh winsock reset

After it runs, reboot the system (it might not even need the reboot to start working)